Image-processing devices capable of generating bitmap data of a boldface character (a character in boldface type) by use of bitmap data expressing a standard character (the character in standard type) are widely known and used today. Such an image-processing device is generally designed to generate the boldface bitmap data by enlarging the drawing area of the standard bitmap data.
For example, an image-processing device disclosed in Japanese Patent Provisional Publication No. HE109-198499 generates a boldface character from a standard character (standard bitmap data) by successively shifting the whole drawing area of the standard bitmap data rightward (for example) dot by dot to a prescribed shift amount while converting (incorporating) each shifted area into the drawing area and thereafter successively shifting the enlarged drawing area (including the above shifted areas) downward (for example) dot by dot to a prescribed shift amount while converting (incorporating) each shifted area into the drawing area.
However, when a boldface character is generated by such an image-processing device, the movement area (enlarged area) regarding each dot in the drawing area of the standard bitmap data forms a square or rectangular shape, by which edges of the generated boldface character can be expressed unnaturally especially when the boldface character is generated from a character having an oblique element (such as the character “J” in Gothic font and italic characters) even though ideal result can be obtained when the boldface character is generated from a character made of horizontal and vertical elements only (such as the character “H” in Gothic font).